Since knowledge, thinking, and rational action are properties of the
individual, since the choice to exercise his rational faculty or not depends on
the individual, man’s survival requires that those who think be free of the
interference of those who don’t. Since men are neither omniscient nor
infallible, they must be free to agree or disagree, to cooperate or to pursue
their own independent course, each according to his own rational judgment.
Freedom is the fundamental requirement of man’s mind.